Dreams - make them good and make them big.

[anjou]

Im not sleeping too well of late and so to while away the darkest hours of the night, ive turned my thoughts away from counting sheep to a mental excersise of designing the perfect ship for the ultimate circumnav voyage.

Im lookin for some input of ideas and am debating the pros and cons of Ali vs Steel hulls.

Some of the main issues to be covered are structural integrity, corrosion, maintenence etc.

Which material would best serve the purpose, and why?

[Wotname]

Gosh An. this is a big ask. So many unsaid variables - like how long is the design lifespan of the hull, what level of luxury is required. You said ship so assuming bigger that the average 30 to 50 footer?

Hard to go past steel for anything of size - which no doubt is the reason why big ships are steel .

Ferro should be a contender but again will depend on size and required designed lifespan.

[anjou]

Well, as it says, 'Dreams, - make them good and make them big'
No point having half a dream is there? Whilst your snoozing away, you might as well let rip with your fantasies and let em run wild.

So, its a ship. That rules out GRP and ferro as far as im concerned. Grp simply wouldnt be rigid enough to withstand the tortional stresses and ferro would be too cumbersome and heavy. Ok for a work barge and yacht but not a bluewater cruiser.


With over 40,000 shipping containers going AWOL each year into the hogwash, the odds of hitting one are certainly a risk to be factored in and im concerned that maybe ali would peel open too easily

[Wotname]

OK, lets make 'em big then. Go steel or go home - as this is a RTW ultimate ship (presumably not Titanic size), I would want to be able to go high latitudes and not worry overly about ice thus ruling out Ali.
Steel is also much easier to weld decently and more tolerant of dissimilar metals.
Need to consider excellent design principles regarding internal corrosion but if done properly - no water entrapment, no corners (all edges radiused), correctly sandblasted and coated, properly insulated. I suppose if design life is short say 5 to 10 years then one could forgo the internal corrosion aspects.

What advantages does Ali have?? I can't think of any for this project.

But I don't think you really need any input from us, you know this stuff already

[anjou]

Nothing is written in stone, im always open to good ideas and new thoughts. Thats the true wonder of a group like CF, it provides a good data base of knowledge.

I do wonder if there are any recorded incidences of metal fatigue in Alum hulls and having owned a few Land Rovers, the dissimilar metals corrosion is a huge problem, where ali meets steel. Another problem is the corrosion caused by road salt.

So I guess it has to be steel.

So, ....this contentious question has to be asked. One hull or two?

[Jimbo485]

1 hull for high latitudes and 2 hulls for the rest.
(Unless you are thinking of LOA >80´, then maybe 2 hulls for high latitudes as well.)

But you are opening a can of worms with your last question!

[Jimbo485]

Of course, 2 hulls means you must go with Alum.
1 hull means steel or alum.

[Wotname]

Originally Posted by anjou

............So I guess it has to be steel.

So, ....this contentious question has to be asked. One hull or two?

Originally Posted by Jimbo485

1 hull for high latitudes and 2 hulls for the rest.
(Unless you are thinking of LOA >80´, then maybe 2 hulls for high latitudes as well.)

But you are opening a can of worms with your last question!

Huh, we talking ship here - sorta thought that would be well over 100 ft.
Two hulls - never even considered the idea but lets consider it now it has been mentioned.

Gut feeling is the structural integrity would be an issue for two ship sized ocean going hulls joined together but you guys are the marine design wallas, not me

[Doodles]

Originally Posted by Jimbo485

Of course, 2 hulls means you must go with Alum.
1 hull means steel or alum.

That would be my choice and 45-50' seems about right for a couple. What else we need besides two engines and some sails?

[anjou]

I did say make it big, so following your assumption its > 80', I would add that its maybe nearer to > 180'

If you say 'Big', you gotta mean it.
Forget boat, this is deff SHIP.

See, I have a problem, I do get sea sick, so I dont want to be sloshing round like a cork on the briney sea, and I do so hate living like a mountain sheep at 30 degrees, trying to stay upright when your world is sideways.

So it has to be a cat. Two hulls = twice the fun, twice the space and twice as many places to be visited with a shallow draft.

[anjou]

Originally Posted by Doodles

That would be my choice and 45-50' seems about right for a couple. What else we need besides two engines and some sails?

Who mentioned a couple?

Hell, if I was doing a voyage round the world, I would want to be able to take a few friends and family along too, so a few extra cabins would be essential.

[Doodles]

Originally Posted by anjou

Who mentioned a couple?

Hell, if I was doing a voyage round the world, I would want to be able to take a few friends and family along too, so a few extra cabins would be essential.

Ooops, o.k. so my 45-50' is way off and we're talking BIG and lots of friends and guests! I think Steve Dashew's "Wind Horse" is your ride. Not a cat but I wouldn't care. Nice boat.

http://dashewoffshore.com/pdfs/SS21_Dashew.pdf

[anjou]

Wind Horse is a nice boat but no where near big enough. More than double the length and 4x the beam for a start

[Doodles]

O.K., o.k., here's my last suggestion. World's largest luxury catamaran. 44 meters ... big enough?

Luxury Catamaran HEMISPHERE - Sailing Yacht

[anjou]

I did look at production cats, starting with the Sunreef. Also Privelege, but when all is said and done, they are still too small and GRP.

Im thinking give or take 30 cabins, approx 80 guests capacity. Factor in swimming pool, hot tub, gym, hair and beauty salon, dining /ball room, sun deck, cinema etc, plus water toys like PWCs, sailing dink, surf boards, big game fishing chairs, scuba gear, mini sub etc Would like a pool room but balls wouldnt stay put long enough to take a pot.

So to sum up. Steel, cat, > 180', 30 cabins,...........what else?